Cash machine manufacturer NCR has announced plans to cut 650 jobs at its plant in Dundee.
A security presence at NCR as staff learned their fate
Speculation over the future of the US firm's operation had been building since it opened a plant in Hungary.
Dundee City Council raised concern that a knock-on effect among suppliers and other businesses could result in the total loss of as many as 1,000 jobs.
NCR blamed the "changing market environment" and competitive pressures for the job losses.
The firm said ATM production would continue at its plant in Budapest, opened just over a year ago, and at factories in Beijing and India.
Staff who learned their fate after being summoned to a midday meeting at the plant expressed anger after NCR said in 2005 that the Hungary operation would "complement" the Dundee factory.
One worker, 42-year-old George Devlin, said: "There were people in there who have worked here all their lives. Dundee is going to be like a ghost town - there is just total anger and disbelief."
About 100 staff have been kept on to make products developed by the company's research department.
The city council's economy chairman, Joe Morrow, said the announcement was a devastating blow.
"This news comes after a long period in which many people have put in a huge amount of effort to rebuild the economy of Dundee," he said.
"I am deeply saddened by the loss of so many jobs at a firm whose operations have been synonymous with Dundee for generations."
NCR, an Ohio company which employs about 28,000 staff worldwide, also specialises in airline and hotel self check-in systems.
The workers learned their fate after being called to a meeting
First Minister Jack McConnell said the Scottish Executive would look closely at the situation.
He said: "I and fellow ministers take this matter seriously. We take the future prosperity of the city very seriously and there will be early meetings to discuss this."
NCR director of manufacturing operations Allan Valentine described the cuts as "difficult but necessary".
He said: "Despite our efforts to take cost out of our operations, it costs us more money to build ATMs on a unit-by-unit basis in Dundee than in any of our other manufacturing plants.
"We cannot continue with our current strategy."
Scottish Enterprise Tayside said it would be helping workers whose jobs were affected, while supporting NCR's research and development facility.
Business growth director Jill Farrell said: "The support we can offer people whose jobs will be affected includes alternative employment and re-training opportunities."
Meanwhile, the union Unison said it was not prepared to discuss redundancy packages with NCR at the moment and would try to save as many jobs as possible.
And Amicus accused NCR of betraying a loyal workforce.